the unit of luminous flux in the International System,equal to the amount of light given out through a solid angle by a source of one candela intensity radiating equally in all directions是什么意思_the unit of luminous flux in the International System,equal to the amount of light given out through a solid angle by a source of one candela intensity radiating equally in all directions在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句